Artificial leg



C. L. FREEMAN ARTIFICIAL LEG Jan. 2, 1934.

Filed July 5, 1929 gwuentoz Carl L. Free/12012 Patented Jan. 2, 1934 UNETED STATE$ r or ies PATEL ARTIFICIAL LEG corporation of Shin Application July 3, 1929. Serial No. 375,650

21 Claims.

My invention relates to an artificial leg including a thigh member adapted for connection with a leg stump, and a shin member plvotally connected at its upper end at a knee joint with the lower end of the thigh member.

The objects of the present improvements include the provision of novel means for controlling the movement at the knee joint of the shin member with respect to the thigh member in a natural manner, when the person upon whom the leg is applied performs the natural movements of walking by swinging the stump, and without requiring much if any movement of the other parts of the body to operate the artificial leg, as is necessitated in other forms of artificial legs.

These and ancillary objects are attained in the present invention, which will hereinafter be set forth in greater detail, and claimed.

A preferred embodiment of the improvements is illustrated in the accompanying drawing forming part hereof, in which Figure 1 is a side perspective view illustrating an embodiment of the improved artificial leg in use upon a man;

Fig. 2, a perspective view with portions broken away illustrating the improved means controlling the knee action or" the leg;

Fig. 3, an end elevation as, in the direction of the arrows 3-3, illustrating the control lever for the improved leg, detached from the leg; and

Fig. 4, a side elevation of a modified embodie ment of the control levers Similar numerals refer to similar parts throughout the several views.

The improved artificial leg indicated nerally at 10, includes a thigh member, prefer-ably in the form of a thigh shell 11, and a or shank member, preferably in the form of a shin shell 12, and the lower end of the thigh shell is pivotally connected with the upper end of the shin shell by a knee bolt '13.

The front lower knee end 14 of the thigh shell, curvesto the rear and fits between side wings 15 formed at the upper end of the shin shell, and the knee bolt 13 extends through suitable registered apertures in the wings l5 and the lower end of the thigh shell.

An improved control lever indicated generally at 17 is pivotally mounted on the knee bolt 13, within the hollow thi h member, and parts of the control lever extend to the rear and downwardly into the hollow shin member through a vertical slot 18 formed at the rear in the lower end of the wall 19 of the thigh shell 11. The knee bolt 13 passes through a bearing aperture 20 formed in the control lever.

The control lever 17 preferably includes a lower arm 21 below the knee bolt, and an upper arm 22 above the knee bolt; and the lever may be formed by side members 23a and 23?), formed of sheet metal, and between the lower arm portions of which may be interposed a spacer block 24 which may be made of wood, and the side members may be secured to the spacer block as by means or" rivets 25.

The lower arm 21 of the control lever depends through the slot 18 into the interior of the shin shell 12, and is secured to the shell 12 as by means of a sleeve 26 which may be formed by a U strap 2'7, the outer ends of which are secured to the interior of the shin shell.

The arm 21 is preferably curved from the knee bolt downwardly, as illustrated; and a resilient pad 28 of felt or the like, is secured to the shin shell and is interposed between the interior surface of the shell and the rear surface 29 of the curved lower arm 21.

The upper arm 22 of the control lever includes a forwardly and upwardly extending inner leg 30, from the upper end of which an intermediate leg 31 extends rearwardly, and an outer leg 32 extends downwardly from the outer end of the intermediate leg 31.

In other words, the upper arm 22 is in the form of a hook extending from the forward side of the knee bolt upwardly, rearwardly and down-- wardly so that an upward force applied at the outer end of the arm 22 applies a downward force at the upper end of the relatively short inner leg tending to rotate the whole control lever about the knee bolt.

The upper arm-of the control lever is preferably formed only by the side members 2311 and 2317, which preferably include at th ir outer upper ends, bearing brackets 33a and 33b; and a transversely extending cord guide member, preferably a grooved roller 34 is pivotally mounted on a shaft 36a, the ends of which are secured in the bearing brackets 33a and 33b. The roller 34 is thus at the rear of and below the knee bolt 1'3.

At the junction between the inner leg 30 and the intermediate leg 31, another transversely extending cord guide member, preferably a grooved roller is mounted between the side members on a shaft 362), the ends of which are secured in the side members 23a and 23b. The roller 35 is thus above and forwardly of the knee bolt 13.

As illustrated, in order to best attain the desired operation of the control lever 17, the rear cord guide roller 34 is located at a greater distance than the forward guide roller 35 from the axis of rotation of the control lever 17 which coincides with the axis of the knee bolt 13.

A resilient tension member 37 is connected at its upper end with the thigh member, and at its lower end with the outer end of the control lever arm 22, as by means of a pin 38.

Control cords 39 are conn cted at their rear end with the rear end of a harness 40 carried on the shoulders of the person 41 upon which the leg is fitted by insertion of the thigh stump 42 into the upper open end of the artificial leg thigh shell 11.

The cords 39 extend from their rear end connection with the harness downwardly through a guide loop 43 on the rear of the thigh member, thence to the rear of and under the roller guide member 3%, thence over the top of the knee bolt 13 between the lever side members 23a and 23b, thence beneath the roller guide member 35, thence through an aperture 44 in the front of the thigh shell wall 19, and thence upwardly to a connection with the front end of the harness 40.

It is to be noted that each of the roller guide members 34 and 35 are mounted directly on the control lever, so that a force applied on either of the guide members applies a torque to the lever, the torques thus applied being opposite to each other.

The modified embodiment 17 of the control lever illustrated in Fig. 4 is similar to the control lever 17, with respect to the location of the rollers, but in the modified control lever 17', the upper arm 22' is not hook shaped and its connection with the roller arm is midway between the rollers, instead of at the end of a hook.

The operation of the improved artificial leg for walking forward, results in movements of the thigh and shin shells or members thereof, which very nearly correspond to the natural movements of a live leg; and the artificial leg is operated primarily by the natural swinging movement of the thigh stump, with little or no exertion by the body and shoulders.

When the thigh stump is raised, the cords 39 lift on the roller 34, thereby causing the roller arm 21 to push backwards against the shin member, and causing the same to move in a natural manner.

' The backward rotary movement of the shin member is limited by the forward roller 35 impinging against and taking up the slack in the cord, and the impinging of the forward roller 35 against the cords causes a rebound in the cords which quickly brings the shin member back to a position in substantial alinement with the thigh member, for carrying the weight of the body thereon.

When the weight of the body is carried on the artificial leg, the lower end surface 45 of the slot 18 strikes against the front of the arm 21, causing the lower end of the arm to push against the resilient pad 28.

The resilient tension member 37 acts as a shock absorber for stopping the return movement of the shin shell to the load supporting position.

The net result of the operation of the control lever by the cords, is to start and stop the swinging movement of the shin member in a manner similar to the natural movements of the same.

Too slow or too rapid a swinging of the shin member prevents the user of an artificial" leg from walking naturally, and increases the work of operating the leg.

When a person using the improved leg hereof is standing and desires to step backwards with the artificial leg or to kneel on the same, a slight lift of the shoulder kicks the shin backward by a pulling of the cords upwards on the roller 34,

In other legs, raising the shoulder straightens the thigh and shin members with respect to each other.

The hook shape of the arm 22 provides a spring action which eases the strain of operating the leg.

I claim:

1. An artificial leg including a thigh member adapted for connection to a thigh stump, shank member, a knee bolt pivotally connecting the lower end of the thigh member with the upper end of the shank member, a control lever rotatably mounted on the knee bolt, the control lever including an arm depending from the knee bolt and engaging the shank member for rotating the shank member when the arm rotates, a transversely extending cord guide member secured directly on the lever at the rear of the knee bolt l I and another transversely extending cord guide member secured directly on the lever forwardly of the knee bolt, and a control cord extending from the rear downwardly and under the first guide member, thence over the top of the knee 3.1-5

bolt, and thence beneath the other guide member the ends of the control cord being adapted for connection with a shoulder harness.

2. An artificial leg including a thigh member adapted for connection to a thigh stump, a shank member, a knee bolt pivotally connecting the lower end of the thigh member with the upper end of the shank member, a control lever rotatably mounted on the knee bolt, the control lever including an arm depending from the knee bolt and engaging the shank member for rotating the shank member when the arm rotates, a roller cord guide member secured directly on the lever at the rear of the knee bolt and another roller cord guide member secured directly on the lever forwardly of the knee bolt, and a control cord extending from the rear downwardly and under the first guide member, thence over the top of the knee bolt, and thence beneath the other guide member, the ends of the control cord being adapted for connection with a shoulder harness.

S. An artificial leg including a thigh member adapted for connection to a thigh stump, a shank member, a knee bolt pivotally connecting the lower end of the thigh member with the upper end of the shank member, a control lever rotatably mounted on the knee bolt, the control lever including an arm depending from the knee bolt and engaging the shank member for rotating the 1 shank member when the arm rotates, a transversely extending cord guide member secured on the lever at the rear of and below the knee bolt and another transversely extending cord guide member secured on the lever above and forwardly of the knee bolt, and a control cord extending from the rear downwardly and under the first guide member, thence over the top of the knee bolt, and thence beneath the other guide member, the ends of the control cord being adapted for connection with a shoulder harness.

4. An artificial leg including a thigh member adapted for connection to a thigh stump, a shank member, a knee bolt pivotally connecting the lower end of the thigh member with the upper end of the shank member, a control lever rotata bly mounted on the knee bolt, the control lever including an arm depending from the knee bolt and engaging the shank member for rotating the shank member when the arm rotates, a roller cord guide member secured on the lever at the rear of and below the knee bolt and another roller cord guide member secured on the lever above and forwardly of the knee bolt, and a control cord extending from the rear downwardly and under the first guide member, thence over the top of the knee bolt, and thence beneath the other guide member, the ends of the control cord being adapted for connection with a shoulder harness. V

5. An artificial leg including a thigh member adapted for connection to a thigh stump, a shank member, a knee bolt pivotaily connecting the lower end of the thigh member with the upper end of the shank member, a control lever rotatably mounted on the knee bolt, thecontrol lever including an arm depending from the knee bolt and engaging the shank member for rotating the shank member when the arm rotates, a transversely extending cord g'uidemember secured on the lever at the realor the knee bolt and another transversely extending cord guide member secured on the lever forwa'rdlyof the knee bolt, a control cord extending from the rear downwardly and under the first guide member, thence over the top of the knee bolt, and thence beneath the other guide member, the ends of the control cord being adapted for connection with a shoulder harness, and a resilient member connecting the thigh member with the lever at the rear of the knee bolt. 7

6. An artificial leg including a thigh member adapted for connection to a thigh stump, a shank member, a knee bolt pivotally connecting the lower end of the thigh member with the upper end of the shank member, a control lever rotatably mounted on the knee bolt, the control lever including an arm depending from the knee bolt and engaging the shank member for rotating t1 e shank member when the arm rotates, a roller cord guide member secured on the lever at the rear of the lmee bolt and another roller cord guide member secured on the lever forwardly of the knee bolt, a control cord extending from the rear downwardly and under the first guide member, thence over the top of the knee bolt, and thence beneath the other guide member, the endsof the control cord being adapted for connection with a shoulder harness, and a resilient member connecting the thigh member with the lever at the rear of the knee bolt.

'7. An artificial leg including a thigh member adapted for connection to a thigh stump, a shank member, a knee bolt pivotally connecting the lower end of the thigh member with the upper end or" the shank member, a control lever rotatably mounted on the knee bolt, the control lever including an arm depending from the knee bolt and engaging the shank member for rotating the shank member when the arm rotates, a trans versely extending cord guide member secured on the lever at the rear of and below the knee bolt and another transversely extending cord guide member secured on the lever above and forwardly of the knee bolt, a control cord extending from the rear downwardly and under the first guide member, thence over the top of the knee bolt, and thence beneath the other guide memher, the ends of the control cord being adapted for connection with a shoulder harness, and a resilient member connecting the thigh member with the lever at the rear of the knee bolt.

An artificial leg including a thigh member adapted for connection to a thigh stump, a shank member, a knee bolt pivotally connecting the lower end of the thigh member with the upper end oi the shank member, a control lever rotatabiy mounted on the knee bolt, the control lever including an arm depending from the knee bolt and engaging the shank member for rotating the shank member when the arm rotates, a roller cord guide member secured on the lever at the rear of and below the knee bolt and another roller cord guide member secured on the lever above and forwardly of the knee bolt, a control cord extending from the rear down wardly and under the first guide member, thence over the top of the knee bolt, and thence be heath the other guide member, the ends of the control cord being adapted for connection with a shoulder harness, and a resilient member conmeeting the thigh member with the lever at the rear of the knee bolt.

9. An artificial leg including a thigh member adapted for connection to a thigh stump, a shank member, a knee bolt pivotally connecting the lower end of the thigh member with the upper end of the shank member, a control lever ro tatably mounted on the knee bolt, the control lever including an arm and a hook, the arm depending from the knee bolt and engaging the shank merhber for rotating the shank member when the arm rotates, a transversely extending cord guide member secured on the hook at the rear of the knee bolt and another transversely extending cord guide member secured on the hook forwardly of the knee bolt, and a control cord extending from the rear downwardly and under the first guide member, thence over the top of the knee bolt, and thence beneath the other guide member, the ends of the control cord being adapted for connection with a shoulder harness.

l0. An artificial leg including a thigh member adapted for connection to a thigh stump, a shank member, a knee bolt pivotally connecting the lower end of the thigh member with the upper end of the shank member, a control lever 1'0- tatably mounted on the knee bolt, the control lever including an arm and a hook, the armdepending from the knee bolt and engaging the shank member for rotating the shank member when the arms rotates, a roller cord guide member secured on the hook at the rear of the knee bolt and another roller cord guide member secured on the hook forwardly of the knee bolt, and a control cord extending from the rear downwardly and under the first guide member, thence over the top of the knee bolt, and thence beneath the other guide member,.the ends of the control cord being adapted for connection with a shoulder harness.

11. An artificial leg including a thigh member adapted for connection to a thigh stump, a shank member, a knee bolt pivotall'y connecting the lower end of the thigh member with the upper end of the shank member, a control lever ro tatably mounted on the knee bolt, the control lever including an arm and a hook, the arm depending from the knee bolt and engaging the shank member for rotating the shank member when the arm rotates, a transversely extending cord guide member secured on the hook at the rear of and below the knee bolt and another transversely extending cord guide member secured on the hook above and forwardly of the knee bolt, and a control cord extending from the rear downwardly and under the first guide member, thence over the top of the knee bolt, and thence beneath the other guide member, the ends of the control cord being adapted for connection with a shoulder harness.

12. An artificial leg including a thigh member adapted for connection to a thigh stump, a shank member, a knee bolt pivotally connecting the lower end of the thigh member with the upper end of the shank member, a control lever rotatably mounted on the knee bolt, the control lever including an arm and a hook, the arm depending from the knee bolt and engaging the shank member for rotating the shank member when the arm rotates, a roller cord guide member secured on the hook at the rear of and below the knee bolt and another roller cord guide member secured on the hook above and forwardly of the knee bolt, and a control cord extending from the rear downwardly and under the first guide member, thence over the top of the knee bolt, and thence beneath the other guide member, the ends of the control cord being adapted for connection with a shoulder harness.

13. An artificial leg including a thigh member adapted for connection to a thigh stump, a shank member, a knee bolt pivotally connecting the lower end of the thigh member with the up- I per end of the shank member, a control lever rotatably mounted on the knee bolt, the control lever including an arm and a hook, the arm depending from the knee bolt and engaging the shank member for rotating the shank member 1 when the arm rotates, a transversely extending cord guide member secured on the hook at the rear of the knee bolt and another transversely extending cord guide member secured on the hook forwardly of the knee bolt, a control cord Ii extending from the rear downwardly and under the first guide member, thence over the top of the knee bolt, and thence beneath the other guide member, the ends of the control cord being adapted for connection with a shoulder harness,

land a resilient member connecting the thigh member with the lever at the rear of the knee bolt.

14. An artificial leg including a thigh member adapted for connection to a thigh stump, a shank .member, a knee bolt pivotally connecting the lower end of the thigh member with the upper end of the shank member, a control lever rotatably mounted on the knee bolt, the control lever including an arm and a hook, the arm depending '1 from the knee bolt and engaging the shank memher for rotating the shank member when the arm rotates, a roller cord guide member secured on the hook at the rear of the knee bolt and another roller cord guide member secured on the hook forwardly of the knee bolt, a control cord extending from the rear downwardly and under the first guide member, thence over the top of the knee bolt, and thence beneath the other guide member, the ends of the control cord being adapted for connection with a shoulder harness, and a resilient member connecting the thigh member with the lever at the rear of the knee bolt.

15. An artificial leg including a thigh member adapted for connection to a thigh stump, a shank 1 member, a knee bolt pivotally connecting the lower end of the thigh member with the upper end of the shank member, a control lever rotatably mounted on the knee bolt, the control lever including an arm and a hook, the arm depending from the knee bolt and engaging the shank member for rotating the shank member when the arm rotates, a transversely extending cord guide member secured on the hook at the rear of and below the knee bolt and another transversely extending cord guide member secured on the hook above and forwardly ofthe knee bolt, a control cord extending from the rear downwardly and under the first guide member, thence over the top of the knee bolt, and thence beneath the other 'guide member, the ends of the control cord being adapted for connection with a shoulder harness, and a resilient member connecting the thigh member with the lever at the rear of the knee bolt.

16. An artificial leg including a thigh member adapted for connection to a thigh stump, a shank member, a knee bolt pivotally connecting the lower end of the thigh member with the upper end of the shank member, a control lever rotatably mounted on the knee bolt, the control lever including an arm and a hook, the arm depending from the knee bolt and engaging the shank member for rotating the shank member when the arm rotates, a roller cord guide member secured on the hook at the rear of and below the knee bolt and another roller cord guide member secured on the hook above and forwardly of the knee bolt, a control cord extending from the rear downwardly and under the first guide member, thence over the top of the knee bolt, and thence beneath the other guide member, the ends of the control cord being adapted for connection with a shoulder harness, and a resilient member connecting the thigh member with the lever at the rear of the knee bolt.

17. A control lever for an artificial leg and the like adapted for rotating about an axis, and including portions extending on opposite sides of the axis, and a pair of spaced cord guide members secured directly on the lever at opposite sides of the axis, one of the guide members being normally forward of and above and the other being normally rearward of and below the axis.

18. A control lever for an artificial leg and the like adapted for rotating about an axis, and including portions extending on opposite sides of the axis, and a pair of spaced roller cord guide members secured directly on the lever at opposite sides of the axis, one of the roller guide members being normally forward of and above and the other being normally rearward of and below the axis.

19. An artificial leg comprising a thigh section, a shin section pivotally connected therewith, a control member mounted on said shin section and having a portion projecting above the pivotal axis and having guide means rigidly mounted on said portion and spaced radially with reference to said axis, one of said means being located forwardly and above said axis when the leg is in normal straightened position, a suspender cord for said leg extending under both guide means and having its intermediate portion between said guide means passing above said pivotal axis, said cord exerting a greater force on said forward guide and a lesser force on said other guide means as said shin section passes to a bent position.

20. An artificial leg including a thigh member adapted for connection to a thigh stump, a shank member, means pivotally connecting the lower end of the thigh member with the upper end of the shank member, a control lever mounted for rotation coaxial with the pivotal connecting means and engaging the shank member, the control lever including portions extending on opposite sides of the pivotal connecting means, and spaced cord guide members secured directly on the lever at opposite sides of the pivotal connecting means, the normally forward cord guide member being normally above the axis of the pivotal connecting means and the normally rearward cord guide member being normally below the normally forward cord guide member and the distance of the normally forward cord guide member from the axis of the pivotal connecting means being less than the distance of the normally rearward cord guide member from the axis of the pivotal connecting means, and a control cord operatively associated with the guide members on the lever.

21. A control lever for an artificial leg and the like adapted for rotating about an axis, and including portions extending on opposite sides of the axis, spaced cord guide members secured directly on the lever at opposite sides of the axis, one of the guide members being normally forward of and above the axis, and the other cord guide member being normally rearward of the axis and below the normally forward cord guide member, and the normally rearward cord guide member being spaced radially from the axis a greater distance than the normally forward cord guide member.

CARL L. FREEMAN. 

